What is Privacy by Design?
Privacy by Design is a principle in which privacy protection is built in from the very start of a system or process. Instead of adding privacy after the fact, it is taken into account from the design stage in the architecture, technology and decision-making.
It is a mandatory requirement under the GDPR (General Data Protection Regulation), Article 25.
🧠 Core principles of Privacy by Design
| Principle | Explanation |
|---|---|
| Proactive, not reactive | Prevent privacy issues before they arise |
| Privacy on by default | Data protection is the default, not optional |
| Built into the design | Privacy is not an add-on, but fundamental to the system or process architecture |
| Full functionality | Strike a balance between privacy and other goals (such as usability and security) |
| End-to-end protection | Privacy applies across the full data lifecycle (from collection to deletion) |
| Transparency and control | Users must know what is happening with their data |
| Accountability | Organisations must demonstrate compliance |
These principles were developed by Dr. Ann Cavoukian and have since been incorporated into European legislation.
🧱 Practical measures
| Measure | Explanation |
|---|---|
| Data minimisation | Collect only data that is strictly necessary |
| Pseudonymisation / encryption | Protect data in storage and in transit |
| User roles and permissions | Restrict data access to what is strictly necessary |
| Logging and auditing | Track who does what with personal data |
| Privacy Impact Assessment (PIA) | Analyse privacy risks ahead of a project |
| Enforcing retention periods | Delete or anonymise data once the purpose has been achieved |
🔐 Relationship to Security by Design
| Aspect | Privacy by Design | Security by Design |
|---|---|---|
| Aim | Protection of personal data | Protection of all digital assets |
| Legally required | Yes, under the GDPR | Not always legally required, but strongly recommended |
| Overlap in techniques | Encryption, access control, logging | Same, but more broadly applicable |
The two principles are often complementary and are typically applied together within NORA, BIO and IEC 62443 frameworks.
🏭 Privacy by Design in an OT context
Although Operational Technology (OT) traditionally processes little personal data, this is becoming more common:
| Application | Privacy risk |
|---|---|
| Building access systems | Processing of names, access logs and CCTV images |
| Smart meters / sensors | Energy or behavioural data of residents or employees |
| SCADA with login functionality | Logging of user actions, passwords and IP addresses |
Privacy must also be considered in OT, especially when OT systems are connected to IT or cloud environments.
📌 In summary
Privacy by Design means protecting personal data from the drawing board onward. By building privacy into technology, processes and policy, you not only comply with the GDPR, but also avoid reputational damage and data breaches.